Cyclic limit mechanism



Sept. 13, 1932.

. F. A, HERBERT 1,877,314

QYCLIG LIMIT MECHANISII Filed, May 2a. 1930 s Sheets-Sheet 1 gimme F; A.HERBERT 1,877,314

CYCLIC LIIIT IBCHANISI Filed lay 28 1950 5 Sheets-Sheet 2 Sgpt. 13 1932.

P 1 1932- F. A. HERBERT 1,877,314

CYCLIC LIMIT MECHANI SH Filed May 28, 1930 3 Sheets-Sheet 5 gvvuwntocPatented Sept. 13, 1932 .FRANK A. HERBERT, on CINCINNATI, orrio cYcLIoLIMIT MECHANISM Application filed May as, 1930. s rial Noi-456,4611

The present invention relates to a cyclic multiple limitmechanismandisespecially adapted to use with an extension-table of theautomatic leaf shifting type.

- An object of the invention is to provide control means for a pairofoppositely reciprocating members whereby such members may first bepulled apart and halted at a primary limit, then retracted partially andthen pulled apart to a second limit and then retracted to the initialposition for repetition of the same cycle of operations.

The device of' the'invention. accomplishes these and other objects bythe means described herein and disclosed in the accompanying drawings,in which:

Fig. 1 is a bottom planview of an extension table embodying adevice-of'the invention, part being broken away;

Fig. 2 is a view taken online 22 of Fig. 1'.

Fig. 3 is a view similar to Fig. 2"but showing the table i'n its firstopening position with-the device of the invention limitingsaidopening-movement.

Fig. 4 is an enlarged-fragmental view taken on line 44: of Fig. 3. A

Fig. 5 is an enlarged perspective view of the device, of the inventionmount'ed'upona fragment ofthe table shown in Fig. 1'. i

In describingthe usefulapplication of the device of the presentinvention an automatic leaf. shifting extension table-i s'usedas anexample, the invention being however not liinitedto this specific use asWill'be readily appreciated.

The'automatic leaf shiftin'gtable'will be briefly, described' so thata-clear idea of a typical cycle of'operations of the limit stop will be.had. The table structure comprises generally a frame structure whichcarries a pair of'shiftable table'sections and an extension leafallhaving certain predetermined relative movements, which when preciselyearriedout, separate the table sections, raise the normallysubmergedleaf to the plane of the table sections and'then join the leafand sections; and bya subsequentse-ries of" operationsseparate the tablesection from-the leaf, submerge the leaf and *therr-j'oin the sectionsover thesubmerged' leaf: With u a UNITED STATES PArEurfopmcs Y meanssuch as is provided by the present'invention these operations requirecare and skill; and failure to properly execute any of thenecessarymovements requires the opera-' tor to begin all over again. i 5

Referring to the drawings the table "con- 4' sists' of a framecomprising'spaced bars-1O which carry the legs 1-1 and which are connected together by a cross. board-12 There are two identical structuresassociated withthe'members lO so that a description of'one will servefor both. The frame and legs support the table structure and they do notmove in spreading, the table to enlarged position.

Each member carries a freely rotatable gear 13 and has slide grooves 14and 15 in its opposite sides. A splined or'reciprocat ing. slidableconnection to the two table top sections 16and'17 is-had by the slides'18 and i 19 respectively, which carry keys 20 disposed 37 in thegroovesli'and 15. ,Slide18'is secured to top section 16-a'nd slide19'is securedto top section 17, by any means such as screws 21' being used to mountthe slidesand spacers 22'to the underside of the top sections. Each Iofthe slides 18 and 19 have racks 23 secured f totheir bottoms forengagement with gears 18. Thetop sections thusmove uniformly in oppositedirections relative to the frame structure and are guidedin the groovesby the slides, I

An extension leaf 24' normally rests be neath the overhangingand'meeting portions of'the topsections and is'so mountedand arrangedthat when the topsections 16 and 17 are pulled aparta given distance,the exten+ sion leaf 24. is raised bodily to the plane of the topsections'whichmay then be pushed together to forman enlarged table topwith the leaf 24 between them. The means where by this is accomplishedcomprise bars 25 and 26'disposed close to the ends of the leaf: 24 andis secured thereto .by screws 27. An 0E- set roller 28'projectsoutwardly adj acent each endof bars 25 and 26 and cooperates with araising and'loweringcam 29 mounted onthe flanges 30 of the top sections.springv urged hingedly mounted lifting. member 31 is secured by springhingest32. and normally urges the extension leaf 24Eupwardly and astionsare separated at predetermined distance and the edge 36 ofthe thenperpendicular member 31 holds the extension at the proper level so thatdowels 37 and holes 38 on the" top section and extension will mate whenthe top sections are pushed together? In order to retirethe extension 24to its. submerged position as in Fig. 2, the top sec ,tionslfi and-1?are now spread apart to a greaterdistance than before in order to havespring hinge leaf 39 on member 31 permit a stud 40 (see Fig. 4) to firstturn the leaf and pass beyond it so that upon movement of the top.sections toward each other the stud will abut leaf 39 which' can not bemoved in the opposite direction. The force applied to the topsectionsnow causes the stud to bodily depress me'mber 31and relievetheextension whichnow descends gradually underthe influence of rollers 28on cams 29 andthe top sectionszare then pushed into abutment.

V The structural details just set forth form no part' of the presentinvention which is concerned with a control or cyclic progressivelimit-mechanism for a series of manual movements necessaryto properlyoperate a device such as the previously described table without-theexercise of any particular care on the part of the operator. r V pAttention-is now directed to Fig. 5 wherein the cyclic progressive limitstop is shown arranged forsuccessive movement of the table 'top sectionsat two different limits which are vital t0 the operativeness of thepreviously described mechanism. .The stop mechanism of the presentinvention consists essentially ofa plate 41 pivoted adjacent one end at42 to: raise and lower in a vertical plane (see Fig.2) within limitsdefined by a slot 43and a fixed pin 44. Extending from the exposed faceof the plate is .a cam track 45, and a curvedstop 46 spaced from andcurved about andover the track 45. At the end 47 of the plate is an endstop 48 which continues along the top edge of theplate to form a track49 which overhangs the. stop 46 and the major portion of track 45. Agravity actuated gate track 50 is pivoted on plate 41 for movement fromits normally pendant position to contact the tapered end 51 of track 45to provide a continuous track section against which a lug such as52,"(see Figs. 2 and 3) fixed on cross board 12, may ride, therebylifting the plate 41bodily and, asthe plate is moved with the slide 18,disposing lug 52 beneath track 45. Continued'relative movementcauses thelug '52 topass beyond the end 53 of track 45 whereupon the lug engagesthe stop 46. This the gate track 50 from turning so that the lug 52 onthe frame'rides along the under curved face of stop 46 and out of theway or passage 54 between the stop 46 and end 53 of track 45 whereuponthe plate 41 drops bodily about its pivotal mounting 42 until the track49engages it. At this time the table has the extension. leaf 24 sition.

When theleaf24 isto be submerged and the table again reduced to itsoriginal length, the top sections are merely pulled apart again,

this time for a greater distance than, before, so that the leaf retlringmechan sm may op crate. The top sections are merely pulled apartuntilthe lug 52 ridingbeneath track 49 engages the stop 48. Then thesections are pushed together allowing the lug 52 to ride in an operativepoback beneath track 49 to the end 55 when plate 41 drops by gravity toits limit and the lug52 strikesgate track 50 andswings it aside untilthe parts assume the position shown in Fig. 2, when'the table iscompletely closed. At this time the device is conditioned to repeatthecycle of operations.

. It-isto be noted that the device of the invention, because of itsconvenient position in a vertical position in the practical embodimentshown, may employ the force of gravity. Otherforce s, e. g. springforce, maybe resorted to in orderto normallydispose the partsin theposition shown in Fig.2, if it should be-found desirable to dispose theplate t 41 horizontally. In most instances it isdesira-ble to use ametal mounting base 56 to carry the plate 41 andgate track 50 and Sim:ply fasten the base, as byscrews 57 ,to a convenient surface. Whenmounted in this way the device withstands hard usagezwithout looseningor displacement.

I The deviceof the'invent on may be made in various sizesand the spacingbetween stops 46 and 48 and gate track 50 will beunderstood to be variedaccording to the difference between the progressive limits ofmovement ofthe reciprocating or movable members to V be controlled thereby. A lugor stop 58 may be provided on the plate 41 in order to preventcompletely around on its pivotalmounting. I

. What is claimed is 5 1., The combination with a pair'ofmembers havingrelative reciprocating movement of acyclic limit mechanism comprising apivoted plate ,havingspaced stops thereon, a

track portion connecting with one of the V stops, a track portionadjacent and in noncontinuous relation to the other of said stops,

a gate track movable to a position of continuity with the last mentionedtrack portion, said mechanism being mounted on one of the reciprocatingmembers and a lug on the other of said membersandextending into the pathof said stops. y

2. A cyclic progressive limit stop mechanism comprising a pivotallysupported plate, spaced stop members on one face of the plate, a tracksection continuous with one of the stops and overhanging the other ofsaid stops, a second track section on the plate discontinuous with thesecond mentioned stop, a gate track mounted for movement over the plateto and from substantial continuity with said second track section, meanslimiting pivotal movement of the plate and a lug mounted in fixedrelation for engaging said stops.

3. In a device of the class described the combination of a plate mountedfor limited pivotal movement upon a given sliding member, a lug fixedlymounted on a second nonmoving member, a gate track member mounted on theplate in the path of said 'lug and movable thereby, a track portion onthe plate, limiting movement of said gate in one direction and adaptedto form a continuous track with said gate, a stop adjacent one end ofsaid track and spaced therefrom to form a way through which the lug maymove from the bottom face of the track to a position above said track,and a second track portion on the plate overhanging said first track andextending beyond the track and stop and having'a turned portionconstituting a second stop.

4;. The combination with a pair of relatively reciprocable members of acyclic progressive stop mechanism comprising a plate pivoted to one ofthe members for limited movement thereon, a pair of spaced stops on saidplate, a track portion connected with one of said stops, a second tracksection disposed adjacent but disconnected from the other of said stops,a pivoted track member movable to provide at times a continuation of thesecond track section and a lug upon the-second member, the plate beingmovable with its associated member to engage the lug to swing thepivoted track member to permit the lug to ride beneath the second trackto the second stop, then, upon retraction of the plate causing the lugto circumvent the second stop and I engage the first track and itsassociated stop.

5. The combination with a pair of relatively reciprocable members of alug on one of said members and means on the other of said memberscomprising a pivoted plate with spaced stops and fixed and movable tracksections for cooperating with the lug to control the limits ofreciprocation of the members so that the members may move a givendistance only, then upon partial re.- traction be moved to a greaterdistance and larcycle of movements.

6.'In combination a movable relative to the lug, a plate pivoted thereonand'having a'transverse slot,a,pin in the base extending into the slotfor limiton the plate comprising a plurality. of spaced stops and tracksections whereby the plate may successively be halted by each of saidthen retracted to original position for a similug, a b ase member I ingpivotal movement of the plate, an'dmeans' stops'as they engage the lugand then returned to its initial position. y

' 7. The combination with an extension'table having an extension lea-farranged to be raised to and lowered from operative'position bymechanism operated bypredetermined opening and closing movementsrelative to a table supporting frame, of means comprising a lug on thesupporting frame and a cyclic progressive limit mechanism mounted'on arelatively reciprocable portion of the table and comprising a shiftableplate, I

spaced stops on the plate and fixed and movable cam track sectionson theplate for cooperation with the lug. I 8. In a 'device of the classdescribed the combination of a shiftable plate, a movable cam tracksection thereon, a pair of spaced track sections one of which mayconnect with saidmovable section, a primary stop curved about an end ofone of sald track sectlons and spaced therefrom and a final stop connected to the other of said track sections, and a lug fixed adj acenttheshiftable plate and cooperating with said tracks and stops to ef feet amultiple of limits of reciprocation o the shiftable plate.

In testimony whereof, I have hereuntosub- 7 V scribedmy name this 7thday of May, 1930. FRANK A. HERBERT.

